1. The problem statement, all variables and given/known data 2. Relevant equations 3. The attempt at a solution I was absent when the physics instructor explained moment of inertia. I went to his office ,he explained to me the basics of this subject. When i asked him to help me in this question, he told me it is the most difficult question you can see in this course and you should solve it alone. Unfortunately, i could not understand how to solve it although he explained moment of inertia to me in addition,i studied it from the book. A friend of mine told me to seek help from this forum and here i am. This is worth marks and that's why i want you to help me... so please help me if possible, im not looking for the answer, i need the way of sovling it.. Thanks in advance.